Psychology Commons^™

A Meta-Analytic Review Of The Effects Of High Stress On Eyewitness Memory, Kenneth A. Deffenbacher, Brian H. Bornstein, Steven D. Penrod, E. Kiernan Mcgorty

Psychology Faculty Publications

In the past 30 years researchers have examined the impact of heightened stress on the fidelity of eyewitness memory. Meta-analyses were conducted on 27 independent tests of the effects of heightened stress on eyewitness identification of the perpetrator or target person and separately on 36 tests of eyewitness recall of details associated with the crime. There was considerable support for the hypothesis that high levels of stress negatively impact both types of eyewitness memory. Meta-analytic Z-scores, whether unweighted or weighted by sample size, ranged from -5.40 to -6.44 (high stress condition–low stress condition). The overall effect sizes were -.31 for …